And his movement and reflexes!

Look how much trouble Tim Bradley gave Manny with his head movement (people think he lost the fight, which is fair, but he also made Manny miss a TON of punches), and look at how much trouble JMM gave Pac with his movement, range and counter punching.

Pac benefits from fighting bigger but SLOWER guys who are going to chase after him, guys he can pot shot and slip away from. Pea ain't that guy, and neither is Mayweather, which is why Mayweather would have beat his ass and why I think Pea would have gotten the upper hand on him.